Designing for sustainable water and nutrient outcomes in urban developments in Melbourne

Abstract

What is the best way to manage water and nutrients when providing water services for urban developments in Melbourne? Melbourne, as with most other major cities in Australia, is facing stresses on its water supply and degradation of receiving water bodies due to stormwater and wastewater discharges. Urban developments need to address these concerns, however there is still much debate regarding which service provision combinations are preferable. This paper seeks to clarify urban water servicing design principles for conservation of water supplies and prevention of eutrophication. Two developments have been studied: (i) Kalkallo, a representative greenfield site, and (ii) Box Hill, a representative multi-storey brownfield site. Various water and sewerage servicing options, with varying levels of end use management, have been assessed by undertaking water and contaminant balances. Results have demonstrated a self-sufficient residential supply without connection to water mains sacrifices reliability. Reclaimed water stores require significantly less land than stormwater stores placed under the same demand, however stormwater stores more effectively reduce eutrophication risks in Port Philip Bay, the bay Melbourne surrounds. On-site reclaimed water systems are ideally suited to apartment towers because of minimal storage size requirements. End use efficiency should always be a priority for conserving water